In short, in times BC (before campers) our biting species of sandflies
gained a blood meal from birds. The flesh just above the scaly feet
was a favourite place. Sandflies on the seashore zone probably also
used seals as a protein source.

In the mid-1970s I was involved in a study of biting rates of Fiordland
crested penguins at Jacksons Bay, South Westland (the sandflies transmit
a malaria-like disease to the penguins). The sandflies definitely
preferred the penguins to the humans nearby. Away from the penguins, I
got bitten; when I stood near to the penguins they flew past me.

In New Zealand we use the term "sandflies" for the biting insects that
in other english-speaking parts of the world are referred to as
"blackflies" or "buffalo gnats". We are fortunate our species, of the
genus Austrosimulium, do not transit diseases affecting humans such as
the nematode worm causing river-blindness (onchoceriasis).